Digital systems rely on timing subsystems in order to operate properly. Such timing subsystems are vulnerable to timing anomalies, which are difficult to detect.
When dealing with network security including digital systems, timing anomalies can be the result of a spoofing attack. A spoofing attack is a technique used by a hacker or attacker to masquerade or falsify data, unknown to users of the digital system.
A GNNS spoofing attack involves an attempt by a hacker to trick a GNNS receiver, such as a GPS receiver, by broadcasting a signal which is different than the signals received from GPS satellites. The broadcasted signals are designed to appear as normal or standard GPS signals. However, the spoofed signals are modified in such a manner to cause the GPS receiver to produce bad time or timing intervals and/or produce a position at a location determined by the attacker, as opposed to the actual UTC time or the receiver's actual location. Thus, the goal of spoofing in this example is to provide a GPS receiver with a misleading signal and therefore deceive the receiver to use fake signals for positioning and timing calculations, which will not be accurate.
The reliance on GPS within civil infrastructure is an inherent security vulnerability. Individuals, groups, or nations interested in causing harm can target a GPS reliant system, thereby disrupting or disabling swaths of infrastructure including national critical infrastructure such as the financial and power industries, as well as cellular communication systems and automated teller machines (ATMs). In particular, the concern over GPS spoofing, an insidious form of intentional interference whereby a spoofer transmits counterfeit GPS signals to an unsuspecting (and unprotected) receiver. Spoofing is more malignant than jamming, because current civil receivers trust all GPS signals to be true, and therefore cannot warn the user, much less take evasive action, when confronted with counterfeit signals.
While the GPS P-code is heavily encrypted and thus, is hard to spoof, the civilian GPS signal, the C/A code, is relatively easy to spoof because the signal structure, the spread spectrum codes, and modulation methods are open to the public. Insecure civil GPS technology has recently been utilized by critical systems, such as military vehicles, communications systems, banking and finance institutions and the power grid. Consequently, these systems can be severely compromised when subject to a spoofing attack resulting in positioning or timing anomalies.
In the drawings, like reference numbers generally indicate identical or similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.